Polyoxazolidone catalyst

ABSTRACT

OXAZOLIDONES ARE PRODUCED BY REACTING AN ORGANIC ISOCYANATE WITH AN EPOXIDE IN THE PRESENCE OF AN ALKOXIDE OR PHENOXIDE OF A METAL GROUP II-A OR III-A OF THE PERIODIC TABLE OF ELEMENTS. POLYOXAZOLIDONES PRODUCED ACCORDING TO THE PRESENT INVENTION ARE USEFUL STARTING MATERIALS FOR THE MANUFACTURE OF A WIDE VARIETY OF PRODUCTS INCLUDING FOAMS, COATINGS, ADHESIVES, ELASTOMERS, AND THE LIKE.

United States Patent 3,817,938 POLYOXAZOLIDONE CATALYST KaneyoshiAshida, 1-3-20 Nishihara-cho, Shibnya-ku,

Tokyo, Japan, and Kurt 'C. Frisch, 17986 Parke Lane, Grosse Ile, Mich.48138 No Drawing. Continuation-impart of abandoned application Ser. No.115,103, Feb. 12 ,1971. This application Jan 5, 1973, Ser. No. 321,326

Int. Cl. C08g 22/00 U.S. Cl. 260-775 R 17 Claims ABSTRACT OF THEDISCLOSURE Oxazolidones are produced by reacting an organic isocyanatewith an epoxide in the presence of an alkoxide or phenoxide of a metalfrom Group IIA or I]I-A of the Periodic Table of Elements.Polyoxazolidones produced according to the present invention are usefulstarting materials for the manufacture of a wide variety of productsincluding foams, coatings, adhesives, elastomers, and the like.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part of copending application U.S. Ser. No. 115,103,filed on Feb. 12, 1971, and now abandoned.

BACKGROUND OF THE INVENTION The preparation of oxazolidones from anorganic iso cyanate and an epoxide using a quarternary ammonium halideand an alcohol as cocatalysts is disclosed in US. Pat. 3,313,747. It isalso known that zinc bromide catalyzes the foregoing reaction, Sandler,J. Polymer Science A-1, 5, 1481 (1967). It has now been found that thehereinbelow disclosed and claimed metal alkoxides or phenoxide are muchmore effective catalysts for the preparation of oxazolidones and producethese compounds in relatively high yields.

Accordingly, it is an object of this invention to provide provide novelcatalysts for the preparation of oxazolidones.

It is a further object of this invention to provide catalysts which willenable oxazolidones to be prepared efficiently and in relatively highyields.

Still other objects will readily present themselves to one skilled inthe art upon reference to the ensuing specification and claims.

SUMMARY OF THE INVENTION This invention provides an improved process forpreparing oxazolidone and polyoxazolidone products comprising reactingan organic isocyanate with an epoxide in the presence of a catalyticallyelfective amount of a catalyst compound of the formula:

wherein M is a metal from Group II-A or III-A of the Periodic Table ofElements, as classified by the Handbook of Chemistry and Physics, 33rded., pp. 342-343 (1951) having an atomic number between 4 and 56, R is aC to C -alkyl or phenyl, and n is an integer of 2 or 3 satisfying thevalences of M. This classification of elements also ap pears on pages 4and 5 of the Handbook of Chemical Data, edited by F. W. Atack, ReinholdPublishing Corporation, New York, N.Y. (1957).

DETAILED DESCRIPTION OF THE INVENTION The present invention contemplatesreacting an organic isocyanate with an epoxide so as to produce anoxazoli- Patented June 18, 1974 ice wherein M is a metal from Group II-Aor III-A of the Periodic Table of Elements, as classified by theHandbook of Chemistry and Physics, volume 33, pp. 342-343, having anatomic number between 4 and 56, for example, beryllium, magnesium,calcium, strontium, barium, aluminum, gallium, indium, R is an organicradical which is a number of the group consisting of alkyl containingone to five carbon atoms, inclusive, hereinafter referred to as a C to C-alkyl and phenyl and n is an integer of 2 or 3. Particularly preferredare the alkoxides and phenoxides of aluminum, calcium, magnesium,strontium and barbium.

In preparing polyoxazolidones by the reaction of an organicpolyisocyanate with a polyepoxide, the relative amounts of the organicpolyisocyanate and the po1yepox ide are not critical and the producedpolyoxazolidones may be isocyanate-terminated or epoxy-terminated.

The produced polyoxazolidones are useful as starting materials for themanufacture of a wide variety of products. For example,isocyanate-terminated polyoxazolidones can be trimerized to produceisocyanurate foams, coatings, adhesives, elastomers, and the like. Inaddition, isocyanate-terminated polyoxazolidones can be furtherpolymerized using an amine having at least two reactive amino hydrogenatoms, a polycarboxylic acid, a polyol, or mixtures of the foregoing.

The isocyanate-epoxide reaction, catalyzed by the pres ent M(OR)catalysts, is usually carried out at an elevated temperature, preferablyin the range of about C. to about C. for a time period of from about 0.5to about 5 hours. The catalyst is present in an amount sufficient toeffect the formation of the oxazolidone ring. The exact amount ofcatalyst present in any particular instance can vary depending on theprocess conditions but preferably is in the range of about 0.001 weightpercent to about 15 weight percent, based on the weight of thereactants. More preferably, the amount of catalyst present is in therange from about 0.01 weight percent to about 10 weight percent.

The term organic isocyanate as used herein and in the appended claims istaken to means an organic compound containing one or more isocyanate(NCO) groups. Examples of organic monoisocyanates are butyl isocyanateand phenyl isocyanate.

Suitable organic polyisocyanates are those which are commonly used inthe preparation of polyurethanes. Illustrative of such polyisocyanatesare the tolylene diisocyanates (TDI) such as 2,4-tolylene diisocyanate,2,'6- tolylene diisocyanate, the methylene bis(phenyl isocyanates) (MDI)such as 4,4'-methylene bis(phenyl isocyanate), also dianisidinediisocyanate, toluidine diisocyanate, hexamethylene diisocyanate,m-xylylene diisocy anate, 1,5-naphthylene diisocyanate, p-phenylenediisocyanate, 1,4-diethylbenzene-B, ,8-diisocyanate and other diandhigher polyisocyanates. Mixtures of two or more of the above isocyanatescan also be used, such as mixtures of the 2,4- and 2,6-isomers oftolylene diisocyanate, mixtures of the 2,4- and 4,4'-isomer of methylenebisphenyl isocyanate) and the like. In addition to the 4,4'- methylenebis (phenyl isocyanate) or mixtures of the 2,4- isomer and the4,4'-isomer thereof which are employed as the isocyanate component,there can also be used modified forms of these isocyanates. For example,there can be used 4,4'-methylene bis (phenyl isocyanate), or an anadmixture thereof with a minor amount of the 2,4- isomer, which has beentreated to convert a minor proportion generally less than 15% by weightof the starting material, to an artifact of said starting material. For

example, the polyisocyanate component can be methylene bis(phenylisocyanate) which has been converted to a stable liquid at temperaturesof about 10 C. and higher.

Illustrative of another modified form of 4,4'-methylene bis(phenylisocyanate) which can form the polyisocyanate component is the productobtained by treating the former compound, or mixtures thereof with smallportions of 2,4-isomer, with a minor portion of a carbodiimide such asdiphenylcarbodiimide. In addition to the various modified forms ofmethylene bis(phenyl isocyanate)exemplified above there can also beemployed as the polyisocyanate component a mixture of methylenebis(phenyl isocyanate) with methylene-bridged polyphenyl polyisocyanatesof higher functionality. Such mixtures are generally those obtained byphosegenation of corresponding mixtures of methylene-bridged polyphenylpolyamines. The latter in turn, are obtained by interaction offormaldehyde, hydrochloric acid and primary aromatic amines, forexample, aniline, o-chloroaniline, o-toluidine and the like.Particularly suitable and thus preferred are organic polyisocyanatesobtained by the phosgenation of the reaction products of aniline andformaldehyde, represented by the formula:

wherein n is an integer having a value in the range from zero to about10, inclusive.

The term epoxide as used herein and in the appended claims is taken tomean a compound containing one or more epoxide groups. Examples ofmonoepoxides are phenyl glycidy ether and epichlorohydrin.

The polyepoxides may contain aromatic, aliphatic, or

cycloaliphatic groups together with two or more epoxide (males groups.Preferably the polyepoxide is aromatic-based, for example, it containsaromatic groups. Illustrative polyepoxides are:

(1) The glycidyl ethers of polyhydric mononuclear and fused ring phenolssuch as resorcinol, hydroquinone, pyrocatechol, saligenin,phloroglucinol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7dihydroxynaphthalene and the like.

(2) The glycidyl ethers of non-fused polynuclear phenols represented bythe general formula:

wherein R represents to 4 substituents selected from the classconsisting of a halogen and lower-alkyl, A is a bridging group selectedfrom the class consisting of 1'1. l and a single covalent bond, wherein[R and R each represent a moiety selected from the class consisting ofhydrogen, lower-alkyl, lower-cycloalkyl and aryl. Typical of suchcompounds are the bis(glycidyl ethers) of:4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxybiphenyl,4,4'-dihydroxybenzophenone, bis(4-hydroxyphenyl)methane (bisphenol F),

2,2-bis(4-hydroxyphenyl) butane (bisphenol B),

2,2-bis (4-hydroxyphenyl) prop ane (bisphenol A),

1,1-bis(4-hydroxyphenyl) propane,

3,3-bis( 3-hydroxyphenyl pentane,

2- 3-hydroxyphenyl -2 (4-hydroxyphenyl butane,

l-phenyl- 1- 2-hydroxyphenyl) -1- 3 -hydroxyphenyl) propane,

l-phenyl-l l-bis (4-hydroxyphenyl butane,

l-phenyl- 1 l-bis (4-hydroxyphenyl pentane,

l-tolyl-l l-bis (4-hydroxyphenyl) ethane,

bis 3-bromo-4-hydroxyphenyl methane,

2,2-bis 3-bromo-4-hydroxyphenyl propane,

bis (3 -bromo-4-hydroxyphenyl) diphenylmeth ane,

l, l-bis 3-bromo-4-hydroxyphenyl) -1- (2,5 -dibromophenyl ethane,

2,2-bis 3 -bromo-4-hydroxyphenyl propionitrile,

bis 3,5 -dibromo-4-hydroxyphenyl methane,

2,2-bis (3 ,5-dibromo-4-hydroxyphenyl) propane,

bis( 3,5 -dibromo-4-hydroxyphenyl diphenylmethane,

1, l-bis 3,5-dibromo-4-hydroxypenyl -1- 2,5 -dibromophenyl -ethane bis3-bromo-4-hydroxyphenyl sulfone,

bis (3 ,5 -dibromo-4-hydroxypheny1 sulfone.

(3) The glycidyl ethers of novolac resins. The novolac resins are theproducts obtained by acid condensation of phenol, or a substitutedphenol, with formaldehyde and are conventionally represented by thegeneral formula:

Reta ls,

wherein n" has an average value of from about 1 to 12 and R representsfrom 0 to 4 substituents selected from halogen and lower alkyl groups.It is to be understood that the above formula is highly idealized and isan approximation only. A wide range of novolac resins of differingmolecular weights is available commercially, all of which arerepresented approximtaely by the above formula. Since the class ofnovolac resins is so well recognized in the art, the epoxide derivedtherefrom by conversion of the novolacs to their glycidyl ethers (byconventional procedures, for example, reaction with epichlorohydrin)will be referred to hereafter as novolac resin glycidyl ethers.

(4) Dicyclopentadiene dioxide, for example, the compound having theformula:

(5) Vinyl cyclohexene dioxide, for example, the compound having theformula:

0 ric...

(6) The dicyclohexyl oxide carboxylates represented by the generalformula:

wherein R in each instance represents from 0 to 9 loweralkyl groups, andB represents a divalent radical selected from the class consisting of:

O O 0 longer}, frames}. and

wherein R is selected from the class consisting of loweralkylene andlower-oxyalkylene and R is selected from the class consisting oflower-alkylene and arylene. Examples of the dicyclohexyl oxidecarboxylates are:

3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate,

3,4-epoxy-fi-methylcyclohexylmethyl 3,4-ep0xy-6-methylcyclohexylcarboXylate,

bis(3,4-epoxycyclohxylmethyl)maleate,

bis (3,4-epoxycyclohexylmethyl) succinate,

ethylene glycol bis(3,5-epoxy-G-methylcyclohexanecarboxylate) and thelike.

(7) The glycidyl derivative of aromatic primary amines represented bythe formula:

0 (mncracmll wherein n" is an integer of from 1 to 3 and R is anaromatic residue of valency n" selected from the glass consisting ofaromatic residues having the formulae:

-t' -1 FQ'I.

wherein A is a bridging group as hereinbefore defined and m is a numberhaving an average value of from about 0.1 to about 1.0. Illustrative ofsuch compounds are the N,N-diglycidyl derivatives of:

and

percent by Weight to about 85 percent by weight of methylenedianilines,the remainingparts of said mix- 75 ture being triamines and polyaminesof higher molecular weight, said polyamine mixture having been formed byacid condensation of aniline and formaldehyde. The latter polyaminemixtures can be prepared by procedures well known in the art.

Illustrative of the catalysts of the present invention are aluminumphenoxide and the aluminum alkoxides, for example, aluminum methoxide,aluminum ethoxide, aluminum propoxide, aluminum isopropoxide, thealuminum butoxides, and the aluminum pentyloxides.

Also suitable are calcium and magnesium phenoxides and the calcium andmagnesium alkoxides, for example, calcium methoxide, magnesiummethoxide, calcium ethoxide, magnesium ethoxide, calcium propoxide,calcium isopropoxide, the calcium butoxides, the calcium pentyloxides,magnesium propoxide, the magnesium butoxides, magnesium isopropoxide,and the magnesium pentyloxides.

In addition, suitable are beryllium phenoxide, beryllium methoxide,beryllium ethoxide, the beryllium pentyloxides, strontium phenoxide,strontium methoxide, strontium isopropoxide, the strontium butoxides,barium phenoxide, barium methoxide, barium propoxide, the bariumpentyloxides, gallium phenoxide, gallium methoxide, gallium ethoxide,gallium propoxide, the gallium butoxides, indium phenoxide, indiummethoxide, indium ethoxide, the indium pentyloxides, thallium phenoxide,thallium ethoxide, the thallium butoxides, the thallium pentyloxides andthe like.

Polymerizable polyoxazolidones prepared in accordance with the presentinvention can be polymerized in the presence of a catalyticallyeffective amount of a polymerization or curing agent which, depending onthe polymerization conditions and the intended application of thepolymerized product, can range from about 0.001 weight percent to about20 weight percent on the weight of the polyoxazolidone present.Preferably, the polymerization or curing agent is present in an amountin the range from about 0.1 weight percent to about 10 Weight percent.

If it is intended to produce resins having an isocyanurate structurefrom an isocyanate-terminated polyoxazolidone, a trimerization catalystsuch as a tertiary amine can be employed alone or together with acocatalyst. Suitable trimerization catalysts are described in detail inBritish Pat. 1,155,768. Other polymerizable compositions can beformulated by admixing, in the presence of a polymerization or curingagent, an isocyanate-terminated polyoxazolidone with an isocyanatereactive compound such as a polyfunctional amine having at least tworeactive amino hydrogen atoms, a polycarboxylic acid, or a polyol havingat least two hydroxyl groups.

Typical suitable polyfunctional amines are 2-aminophenol,cyclohexylamine, phenethylamine, aniline, 2-ethy1-' hexylamine,ethylenediamine, butylenediamine, xylylenediamine, hexamethylenediamine,dihexylenetriamine, triethylenetetramine, dipropylenetriamine,p-phenylenediamine, 4,4'-methylenedianiline, and the like.

Typical polycarboxylic acids are aliphatic, cycloaliphatic, and aromaticcarboxylic acids such as oxalic acid, malonic acid, maleic acid,glutaric acid, citraconic acid, 1,2-cyclohexanedicarboxylic acid,phthalic acid, 1,8-naphthalenedicarboxylic acid, 3-carboxycinnamic acid,1,2,4- butanetricarboxylic acid, 1,2,4-hexanetricarboxylic acid,l,2,4-benzenetricarboxylic acid, and the like.

Suitable polyols are aliphatic and cycloaliphatic polyalcohols andpolyhydric phenols such as ethylene glycol, diethylene glycol, glycerol,polypropylene glycols, butanediol, triethanolamine, pentaerythritol,bis(4-hydroxy phenyl)methane, sorbitol, resorcinol, trimethylolphenol,pyrogallol, hydroquinone, 1,8-naphthalenediol, cyclohexanediol, and thelike.

Any suitable blowing agent may be employed for such formulations, ifdesired, such as inorganic blowing agents,

for example, water or boric acid, low-boiling hydrocarbons, for example,pentane, hexane, heptane, pentene, heptene, benzene, etc., halogenatedhydrocarbons such as dichlorodifluoromethane, trichlorotrifluorethane,trichlorofluoromethane, and the like. Also suitable are reactive organicblowing agents such as the nitroalkanes, for example, nitromethane,nitroethane, nitropropane, etc., the aldoximes, for example,acetaldoxime, propionaldoxime, etc., acid amides, for example,formamide, acetamide, benzamide, etc., enolizable carbonyl compounds,for example, acetylacetone, acetacetic acid ester, etc., and nitrourea.

Optionally, a surfactant such as a silicone surfactant or a non-ionicsurfactant may also be employed if such formulations are foamed. The useof a surfactant is not always necessary, but it is preferable ininstances where a relatively fine cell structure is desired. Typicalexamples of suitable surfactants are dimethyl-polysiloxane,siloxane-oxyalkylene block copolymers, and the like.

Other optional additives, such as flame retardants and organic orinorganic fillers usually employed in the preparation of polymer foamscan also be employed with such formulations. Some of the flameretardants also tend to decrease the viscosity of the formulation duringcompounding. Illustrative flame retardants are tris(haloalkyl)phosphatessuch as tris(2-chloroethyl)phosphate, tris(2-bromoethyl)phosphate,tris(2,3 dichloroethyl) phosphate, tris(2,3 dibromoethyl)phosphate,monoammonium phosphate, ammonium polyphosphates, sodium borate,bis(2-haloalkyl) 2 haloalkanephosphonates such as bis(2-chloroethyl) 2chloroethane phosphonate, bis(2 chloropropyl) 2 chloropropanephosphonate, bis- (2-bromopropyl) 2 bromopropane phosphonate, antimonyoxides, polyvinyl chloride resins, dialkyl alkanephosphonates such asdimethyl methylphosphonate, dialkyl allylphosphonate, dimethylbenzylphosphonate, diamyl amylphosphonate, trimethyl phosphorothionate,ethylene phenyl phosphorothionate, tetrahalobisphenols such astetrachlorobisphenol A, tetrabromobisphenol A, and the like. Said flameretardants are employed in the formulation in the appropriate amountsnecessary to impart the desired degree of flame retardancy to theresulting cellular polymer.

Suitable illustrative inert inorganic fillers are calcium carbonate,ammonium phosphate, calcium phosphate, ammonium sulfate, silica,asbestos, glass, mica, carbon black, wood flour, antimony oxides, etc.Illustrative organic fillers are the various polymers, copolymers, andterpolymers of vinyl chloride, vinyl acetate, acrylonitrile, acrylamide,styrene, ethylene, propylene, butadiene, divinyl benzene, and the like.Cellulose and starch can also be employed, if desired.

The use of halogen-containing fillers is particularly advantageous sincethe use of such materials imparts additional flame resistance to theproduced resins whether foamed or cast.

The present invention is further illustrated by the following examples.

EXAMPLE 1 Preparation of Oxazolidones With Aluminum Isopropoxide Phenylisocyanate (11.9 grams, 0.1 mole), and phenyl glycidyl ether grams, 0.1mole) are combined in a benzene (50 milliliters) solution of aluminumisopropoxide (0.01 mole) and refluxed for about 7 hours. Thereafter3phenyl-S-phenoxy-methyl 2 oxazolidone is recovered from the reactionmixture. In a similar manner and under the same reaction conditions,phenyl isocyanate and phenyl glycidyl ether are reacted in the presenceof aluminum chloride, ferric chloride, zinc chloride andtetraethylammonium bromide.

The yields of 3-phenyl-S-phenoxymethyl-Z-oxazolidone obtained in eachinstance are compiled in Table I, below.

TABLE I.PREPARATION OF OXAZOLIDONES 3-pheny1-5-phefi1oxymethyi-2- In theforegoing example, aluminum isopropoxide was prepared similar to theprocedure described in Organic Syntheses, vol. III, p. 48 for thepreparation of aluminum butoxide. Calcium ethoxide was prepared by thealcoholysis of calcium hydride with ethanol, based on I.A.C.S. 69, 2605(1947). Magnesium ethoxide was prepared by the procedure described inJ.A.C.S. 68, 887 (1946).

Aluminum phenoxide was prepared by reacting aluminum isopropoxide withphenol producing aluminum phenoxide and isopropanol.

As can be readily seen from the foregoing data, in general asubstantially higher yield of 3-phenyl-5-phenoxymethyl-Z-oxazolidone isobtained with the catalysts of the present invention than with otherheretofore known catalysts.

EXAMPLE 2 Preparation of Oxazolidones With Barium Methoxide Bariummethoxide Was prepared from sodium methylate, barium nitrate and liquidammonia by the methods of Annales de Chimie et de Physique (9), 8, 171and Comptes rena'ue a'e ZAcademie des Sciences, 153, 954, 2.0 g. (0.01mol) of barium methoxide thus prepared, 11.9 g. (0.1 mol) of phenylisocyanate, 15.0 g. (0.1 mol) of phenyl glycidyl ether and 50 ml. ofbenzene were charged into a flask and were heated under reflux for 7hours. After cooling the reactant for one day, 3-phenyl-S-phenoxymethyl-2-oxazolidone was recovered by filtration. The yield ofthe product was 72%.

EXAMPLE 3 Preparation of Oxazolidones With Strontinum IsopentyloxideStrontinum isopentyloxide was prepared by reacting strontinum nitratewith sodium isopentylate employed liquid ammonia as a solvent, in a samemanner as described in Example 2, said sodium isopentylate beingobtained by reacting isopentyl alcohol and sodium metal.

1.75 g. (0.01 mol) of above prepared strontium isopentyloxide, 11.9 g.(0.1 mol) of phenyl isocyanate, 15.0 g. (0.1 mol) of phenyl glycidylether and 50 ml. of benzene were charged into a flask and were heatedunder reflux for 7 hours. 3-phenyl-5-phenoxymethyl-2-oxazolidone wasrecovered by filtration after cooling the reactant. The yield of theproduct was 64%.

EXAMPLE 4 Preparation of Polyoxazolidones with Calcium Ethoxide 14.4grams (0.1 eq.) of Isonate 143L (a registered trademark for a liquefieddiphenylmcthane diisocyanate. Upjohn Co.), 21.9 grams (0.1 eq.) of analiphatic diepoxide (Bakelite ERL-4289, registered trademark, UnionCarbide Corp.), 50 ml. of dry benzene and 1.3 grams (0.01 mole) ofcalcium ethoxide were charged into a flask and were heated at C. for 5hours.

Isonate 143L is a trademark of the Upjohn Company for a liquiddiisocyanate structurally similar to diphenyimethane diisoeyanate havingan average NCO equivalent weight of 144.

11 The polyoxazolidone product was a colourless, viscous quid.

B akelite ERL-4289 is a cycloaliphatic epoxy resin having an averageequivalent weight of 205-216 and having the structure mocorcnmoooca 0 H!on.

EXAMPLE Preparation of Polyoxazolidones With Magnesium Ethoxide 8.7grams (0.1 eq.) of 2,4-tolylene diisocyanate, 18.9 grams (0.1 eq.) ofEpon 828 2 (a registered trademark for a bisphenol A-glycidyl ether,Shell Chemical Co.), 50 ml. of dry benzene and 1.1 grams (0.01 mole) ofmagnesium ethoxide were charged into a flask and were heated underreflux for 5 hours. A colourless, viscous liquid polyoxazolidoneresulted.

EXAMPLE 6 Preparation of Polyoxazolidones With Aluminum IsopropoxideEXAMPLE 7 Preparation of Polyoxazolidones With Aluminum Isopropoxide 144grams (1.0 eq.) of Isonate 143L and 14.4 grams (0.076 eq.) of Epon 828were heated in a flask at 130 C. for one hour, and no change inviscosity was observed.

0.20 gram (0.001 mole) of aluminum isopropoxide was charged into theabove mixture, and the mixture was heated at 130 C. for 2 hours. Ahighly viscous liquid. polyoxazolidone was obtained.

EXAMPLE 8 Preparation of Polyoxazolidones With Aluminum Isopropoxide 18grams (0.125 eq.) of Isonate 143L, 50 grams (0.25 eq.) of Epikote 819 3(a registered trademark for a bisphenol A-diglycidyl ether type epoxyresin, Shell Chemical Co.) and 0.1 grams of aluminum isopropoxide wereheated in a flask at 200 C. for 7 hours. The polyoxazolidone productobtained was a viscous liquid at 200 C. and was a glassy solid at a roomtemperature and had an infra-red absorption band at 1740 1 cm.

EXAMPLE 9 Preparation of Polyoxazolidones With Magnesium Ethoxide 16.6grams (0.125 eq.) of Isonate 901 (a registered trademark for a polymericisocyanate, Upjohn Co.), 50 grams (0.25 eq.) of Epikote 819 and 0.1grams of magnesium ethoxide were heated in a flask at 200 C. for 7hours.

2 Epon 828 is a bisphenol A-epichlorohydrin addnct having an averageepoxy equivalent weight of 189 and an average 0H equivalent weight of1670.

Epikote 819 is a Japanese trademark designation of Shell 0il1(8o. 816 anepoxy resin having an average epoxy equivalent of 0-2 4 Isonate 901@ isa trademark of the Upjohn Company for a polymeric isocyanate producthaving an average NCO equivalent weight or 133.

The polyoxazolidone product obtained was a viscous liquid at 200 C., wasan elastic solid at a room temperature.

The foregoing discussion and the accompanying examples are intended asillustrative. Still other variations within the spirit and scope of thepresent invention will readi- 1y present themselves to one skilled inthe art.

What is claimed is:

1. A process for preparing oxazolidones which comprises reacting anorganic isocyanate with an epoxide in the presence of from about 0.001to about 15 weight percent, based on the reactants present, of acompound represented by the formula:

wherein M is a metal selected from the group consisting of metals ofGroup II-A and Group I[[-A of the Periodic Table of Elements, having anatomic number between 4 and 56; R is an organic radical selected fromthe group consisting of C to C -alkyl and phenyl; and n is an integerhaving a value of 2 or 3.

2. A process for preparing polyoxazolidones which comprises reacting anorganic polyisocyanate with a polyepoxide in the presence of from about0.001 to about 15 weight percent based on the reactants present, of acompound represented by the formula:

wherein M is a metal selected from the group consisting of metals ofGroup II-A and Group III-A of the Periodic Table of Elements having anatomic number between 4 and 56; R is an organic radical selected fromthe group consisting of C to C -alkyl, inclusive, and phenyl; and n isan integer having a value of 2 or 3.

3. A process in accordance with Claim 2 wherein M is aluminum, 'R is C;to C -alkyl, and n is 3.

4. A process as defined in Claim 3 wherein the catalyst compound isaluminum isopropoxide.

5. A process in accordance with Claim 2 wherein said compound isaluminum phenoxide.

6. A process as defined in Claim 2 wherein M is calcium, R is C to C-alkyl, and n is 2.

7. A process as defined in Claim 6 wherein the catalyst compound iscalcium ethoxide.

8. A process as defined in Claim 2 wherein M is magnesium, R is C to C-alkyl, and n is 2.

9. A process as defined in Claim 8 wherein the catalyst compound ismagnesium ethoxide.

10. A process in accordance with Claim 2 wherein said compound ispresent in an amount of from about 0.01 weight percent to about 10Weight percent, based on reactants present.

11. In a process for preparing oxazolidones by reacting an organicisocyanate with an epoxide in the presence of a catalyst, theimprovement which comprises conducting the reaction between theisocyanate and the epoxide in the presence of from about 0.001 to about15 weight percent, based on the reactants present, of a catalystcompound of the formula:

wherein M is a metal selected from the group consisting of the metals ofGroup II-A and Group III-A of the Periodic Table of Elements, having anatomic number between 4 and 56, R is an organic radical selected fromthe group consisting of a C and C -alkyl and phenyl, and n is an integerhaving a value of 2 or 3.

12. A process as defined in Claim 11 wherein M is aluminum, R is a C toC -a1kyl, and n is 3.

13. A process as defined in Claim 12 wherein the catalyst compound isaluminum isopropoxide.

14. A process as defined in Claim 11 wherein M is barium, R is a C to C-alkyl, and n is 2.

15. A process as defined in Claim 14 wherein the catalyst compound isbarium methoxide.

1 1 1 2 16. A process as defined in Claim 11 wherein M is str0n-3,694,406 9/1972 DAlelio 260-307 C tium, R is a C to C -alkyl, and n is2- 3,687,897 8/1972 Clarke 260-307 C 17. A process as defined in Claim16 wherein the catalyst compound is strontium isopentyloxide. MAURICE J.WELSH, JR., Primary Examiner References Cited 5 US Cl. XR. UNITED STATESPATENTS 3,313,747 4/1967 Schramm 260 77.5 R 2602.5 AT, 2.5 A], 47 EP, 5977.5 NC, 77.5 AT, 307 C 3,334,110 8/1967 Schramm 260-77.5 R

f nhulnn STATES PATENT OFFICE CERTIFICATE OF CURECTIQN Patent No.33171938 D d June 1 Inventor) Kaneyoshi Ashida and-Kurt C. Frisch It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shownbelow:

Assignee: Kurt C. FfiSLChE-Ffi Mitsubishi'Chemical Industries Limited,Tokyo,

Japan line ll shouldread: mm

v Col 2, lines 67-8 an an" should read: an

Col. 3, line 15 "phosegenation" should t'ead: phosgenation col. 5 line22 I. 7 should read, v hexyl Col. 5, when (3,5-epoxy" should read;(3,4-e o Col. 5,. line 35 "glass" should read: class Col. 5; line 45should be:

l .JLALDX 4 col. 8 line so "employed" should read anploying Signed andsealed this 28th day of January 1975.

(SEAL) Attest:

McCOY M. GIBSON JR; C. MARSHALL DANN Attesting Officer Commissioner ofPatents USCOMM-DC 603764" 9 0.5. covimmcm' rmm'mc orhc: I959 0-;66-3

F ORM PO-IOSO (10-59) 30L 6, line 37 "percent", second occurrence,should read percen' based I :ol. 8, line 46 "Strontinum should readStrontimn line 49 Y dittoj -ditto'- Col; 8 line 50 I "SEIOIllJIUIH"should read st rontium

